Washing holes is a very difficult and complex process that cannot be seen, so it must be proved experimentally.
Therefore, Han Chang Son, a researcher at the Faculty of Earth Science and Technology, employs a simulation device for flow of drilling fluid in his subject “Drilling fluid” to develop students’ creative thinking faculties by presenting principles and vivid images on washing processes.
The simulation device consists of hole models, a pipe rotary device, a cuttings supply device, a pump, a flow route, a fluid box and a control button.
As the simulation device aims to simulate the flow of drilling fluid and the movement of cuttings, he built two hole models in conformity with actual drilling conditions: Model 1 formed of high intensity rock and Model 2 formed of low intensity rock.
In the lesson, he puts the device in operation to show the students the processes of pressurized fluid supply through the rotary pipe and of cuttings conveyance along the annulus, the difference in the rising speed in the sections of various hole diameters and the process of accumulation of cuttings in widened drilling holes.
With the help of the device, the students are able to realize the following things: Cuttings are not transported out of drilling holes but move in their positions with spiral rotation movement due to pipe revolution. The higher the number of pipe revolution and the viscosity of drilling mud, the stronger the spiral rotation movement gets, so transportation of cuttings really goes well. In the formation with weak rock, hole diameters become wider because of erosion, which leads to the slowdown of the flow velocity and the accumulation of cuttings.
They are also able to find a way to improve drilling fluid processing methods.
© 2021 KumChaek University of Technology